Graphic designers are experts at visual communication. Although graphic designers use photographic images when such images are appropriate, designers often use more abstract images, such as those found in sketches and paintings. This design choice is based upon the information the designer wishes to communicate. A realistic photographic image may sometimes be less effective at conveying information than a stylized image. In many cases, the designer must balance realism and effectiveness.
Many of the details of a photographic image may distract the viewer from the subject of the picture. Perfectly smooth surfaces and detailed edges coupled with a sharp focus can increase detail and, accordingly, increase the number of visual distractions. If the image is made more abstract by removing some details, the viewer sometimes can concentrate on the subject of the image with less distraction. To create an effective image, it therefore is important to select the central information to be conveyed by the picture and eliminate visual information that distracts or confuses the viewer. Sometimes it is desirable to vary the amount of detail across an image in order to direct a viewer's attention to the most important parts of the image.
One important use of illustration is to communicate the unique character that distinguishes the subject. For instance, persons sometime find it easier to identify plants and birds in illustrations than in photographs if in the illustrations an artist emphasizes the important visual information about the plants and birds. In commercial and fine arts, graphic artists have used various techniques to present images and filter visual information. The artist can obscure or enhance certain details in order to direct the viewer's attention to given parts of the image. By controlling the color, size, shape, and orientation of brush strokes, an artist is able to direct the viewer to various details that convey specific information. These techniques avoid distracting the viewer with unnecessary detail. Various techniques of using stylized brush strokes to represent images have been popularized by many of the great impressionist painters, such as Monet, Van Gough, and Sargent.
In short, abstract images are sometimes preferred over photographic images.